The military flight aptitude book has practice tests similar to the AFOQT, but beware, the actual test was much harder. For example, the electrical maze was much more complicated than the practice version, and the math portion had equations I hadn't seen since high school. But at least you'll have some idea of what to expect on the test.

Be aware that the AFOQT exam is timed. You only have a few minutes to answer lots of questions in each category. You have to think quickly and jot your answers extremely fast before moving on to the next question. I studied for this exam for one month straight and was ready to to nail this test down. I did not factor in the time constraints when attempting to complete the exam and as a result scored a low percentage. The books helped me to some degree but you have to really know your stuff and be a fast test taker to get a halfway decent score. Best of luck to you!